The invention relates to photonic crystal tunable microcavities using nonlinear materials.
The introduction of a local defect inside a perfect photonic crystal can generate sharp resonant states within the crystal in the vicinity of the defect. In this way, a photonic crystal can be used to fabricate a high-Q microcavity. The frequency of the resonant modes depends on the size and shape of the defects, and on the refractive index of the materials used in the defect.
Ordinarily, these defects are introduced during crystal fabrication by some mechanical process. Although the frequency of the mode depends on the defect's size, shape, and index of refraction, mechanical alteration of the crystal is not a practical means of tuning the frequency after fabrication.